Abstract
The role of the serotonergic (5-HT) system in the regulation of locomotor activity and consummatory behaviors was studied. Electrolytic and chemical (5, 7-dihydroxytryptamine: 5, 7-DHT) lesions were made in the median raphe nucleus (MR). The effects of these lesions on spontaneous locomotor activity, food and water intake and body weight were then studied. In these experiments, rats on an ad libitum feedingdrinking regimen were housed individually in cages with activity wheels located in a room kept at a temperature of 22+1°C. For each rat, records were kept of its spontaneous locomotor activity, food and water intake, and body weight for 8 weeks before and after the placement of lesion in MR. It was observed that:(1) electrolytic destruction of the MR produced a permanent decrease in locomotor activity, and (2) there were a reduced food intake and a decreased spontaneous activity after intra-MR injection of 5, 7-DHT.
